What are cholesterol and atheroma?

Cholesterol is a lipid (fat chemical) that is made in the liver from fatty foods that we eat. A certain amount of cholesterol is present in the bloodstream. You need some cholesterol to keep healthy. Cholesterol is one factor involved in forming atheroma.

Patches of atheroma are like small fatty lumps which develop within the inside lining of arteries (blood vessels). A patch of atheroma makes an artery narrower, which may reduce the blood flow. A build up of atheroma can cause heart diseases such as angina and heart attacks, stroke, transient ischaemic attack (TIA or 'mini-stroke'), and peripheral vascular disease (narrowing of the arteries to the legs).

What are statins and how do they work?

Statins are a group of drugs that are commonly used to reduce the level of cholesterol in the blood. They include atorvastatin, fluvastatin, pravastatin, rosuvastatin, and simvastatin. They each have different brand names. Statins work by blocking the action of a certain enzyme (chemical) in the liver which is needed to make cholesterol.

Who should take a statin?

Your doctor will advise if you should take a statin. One is usually advised if:

• you have an atheroma-related disease (heart disease, etc). A statin helps to reduce the risk of these conditions getting worse. Or, it can delay the progression of the disease.
• you are at increased risk of developing an atheroma-related disease. For example, if you have diabetes, or other 'risk factors'.

What happens when I take as statin?

You should have a blood test before starting treatment. This checks the level of cholesterol. It also checks if your liver is working properly. After starting treatment, you should have a blood test within 1-3 months to check that the liver has not been affected by the medication. Also, to check the cholesterol level to see how well the statin it is working.

The target for most people on statin treatment is:

• To reduce total cholesterol to less than 4.0 mmol/l and LDL cholesterol to less than 2.0 mmol/l, OR
• A 25% reduction in total cholesterol and a 30% reduction in LDL cholesterol.

Whichever is the biggest reduction.

If the target is not reached, the dose may need to be increased. Once the target level is reached, you should continue to take the statin indefinitely. You should have a blood test every now and then as advised by your doctor or nurse to check that your liver remains healthy.

Note: a statin is just one factor in reducing your risk of developing atheroma-related diseases. Just as important are: eating a healthy diet, not smoking, taking regular exercise, losing weight if you are overweight, reducing blood pressure if it is high, and taking a daily low dose of aspirin if advised to do so. See a separate leaflet called 'Preventing Cardiovascular Diseases' for details.

What are the possible side-effects or problems with statins?

Most people who take a statin have no side-effects, or only minor ones. Read the information leaflet that comes with your particular brand for a full list of possible side-effects. These include: headache, pins and needles, abdominal pain, bloating, diarrhoea, feeling sick, and a rash.

You should tell your doctor if you have any unexpected muscle pains, tenderness or weakness. This is because a rare side-effect of statins is a severe form of muscle inflammation.

You should not take a statin if you have active liver disease, if you are are pregnant or intend to be pregnant, or if you are breast feeding. You should stop a statin if you develop liver disease.

Other drugs to reduce cholesterol and other lipids

Other drugs are sometimes used to lower cholesterol and other blood lipids. These include:

• Anion-exchange resins. These include colestyramine (cholestyramine) and colestipol. They work by binding to bile acids which are passed into the gut from the liver and gallbladder. This stops bile acids being reabsorbed into the bloodstream which has a knock-on effect of lowering cholesterol.
• Fibrates which include bezafibrate, ciprofibrate, fenofibrate, and gemfibrozil. One of these is mainly used if you have a high level of triglyceride (another type of blood lipid) with or without a high cholesterol level.
• Nicotinic acid may be tried if other drugs do not work. It is not used often as it has a high rate of side-effects such as facial flushing, feeling sick, vomiting and headache.
• Ezetimibe is sometimes used in certain situations in combination with a statin, or on its own. It prevents the absorption of cholesterol from the gut.
• Fish oils help to reduce blood lipid levels. These occur naturally in oily fish such as mackerel. This is why at least 1-2 portions of oily fish per week are recommended in a healthy diet. Dietary supplements ('fish oil tablets') are also available, and may be recommended by your doctor.

Can I buy a statin?

Statin drugs are available on prescription and funded by the NHS if your risk of developing an atheroma-related disease is high. However, if you are not in the high risk category, it does not mean you have no risk - just a lesser risk. Drug treatment is not usually prescribed. However, simvastatin 10 mg is now available to buy without a prescription. Some people with a moderate risk buy this low dose statin drug from a pharmacy to lower their cholesterol level.

Opinion is divided as to whether it is a good idea or not for people to buy and take a statin if they are not in the high risk category. Simvastatin 10 mg may lower cholesterol by more than 20% which is thought to be beneficial. However, no specific clinical trials have been done with simvastatin 10 mg in people at moderate risk.